diff options
Diffstat (limited to 'drivers/watchdog/it87_wdt.c')
| -rw-r--r-- | drivers/watchdog/it87_wdt.c | 772 |
1 files changed, 772 insertions, 0 deletions
diff --git a/drivers/watchdog/it87_wdt.c b/drivers/watchdog/it87_wdt.c new file mode 100644 index 00000000..8a741bcb --- /dev/null +++ b/drivers/watchdog/it87_wdt.c @@ -0,0 +1,772 @@ +/* + * Watchdog Timer Driver + * for ITE IT87xx Environment Control - Low Pin Count Input / Output + * + * (c) Copyright 2007 Oliver Schuster <olivers137@aol.com> + * + * Based on softdog.c by Alan Cox, + * 83977f_wdt.c by Jose Goncalves, + * it87.c by Chris Gauthron, Jean Delvare + * + * Data-sheets: Publicly available at the ITE website + * http://www.ite.com.tw/ + * + * Support of the watchdog timers, which are available on + * IT8702, IT8712, IT8716, IT8718, IT8720, IT8721 and IT8726. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/fs.h> +#include <linux/miscdevice.h> +#include <linux/init.h> +#include <linux/ioport.h> +#include <linux/watchdog.h> +#include <linux/notifier.h> +#include <linux/reboot.h> +#include <linux/uaccess.h> +#include <linux/io.h> + + +#define WATCHDOG_VERSION "1.14" +#define WATCHDOG_NAME "IT87 WDT" +#define DRIVER_VERSION WATCHDOG_NAME " driver, v" WATCHDOG_VERSION "\n" +#define WD_MAGIC 'V' + +/* Defaults for Module Parameter */ +#define DEFAULT_NOGAMEPORT 0 +#define DEFAULT_EXCLUSIVE 1 +#define DEFAULT_TIMEOUT 60 +#define DEFAULT_TESTMODE 0 +#define DEFAULT_NOWAYOUT WATCHDOG_NOWAYOUT + +/* IO Ports */ +#define REG 0x2e +#define VAL 0x2f + +/* Logical device Numbers LDN */ +#define GPIO 0x07 +#define GAMEPORT 0x09 +#define CIR 0x0a + +/* Configuration Registers and Functions */ +#define LDNREG 0x07 +#define CHIPID 0x20 +#define CHIPREV 0x22 +#define ACTREG 0x30 +#define BASEREG 0x60 + +/* Chip Id numbers */ +#define NO_DEV_ID 0xffff +#define IT8702_ID 0x8702 +#define IT8705_ID 0x8705 +#define IT8712_ID 0x8712 +#define IT8716_ID 0x8716 +#define IT8718_ID 0x8718 +#define IT8720_ID 0x8720 +#define IT8721_ID 0x8721 +#define IT8726_ID 0x8726 /* the data sheet suggest wrongly 0x8716 */ + +/* GPIO Configuration Registers LDN=0x07 */ +#define WDTCTRL 0x71 +#define WDTCFG 0x72 +#define WDTVALLSB 0x73 +#define WDTVALMSB 0x74 + +/* GPIO Bits WDTCTRL */ +#define WDT_CIRINT 0x80 +#define WDT_MOUSEINT 0x40 +#define WDT_KYBINT 0x20 +#define WDT_GAMEPORT 0x10 /* not in it8718, it8720, it8721 */ +#define WDT_FORCE 0x02 +#define WDT_ZERO 0x01 + +/* GPIO Bits WDTCFG */ +#define WDT_TOV1 0x80 +#define WDT_KRST 0x40 +#define WDT_TOVE 0x20 +#define WDT_PWROK 0x10 /* not in it8721 */ +#define WDT_INT_MASK 0x0f + +/* CIR Configuration Register LDN=0x0a */ +#define CIR_ILS 0x70 + +/* The default Base address is not always available, we use this */ +#define CIR_BASE 0x0208 + +/* CIR Controller */ +#define CIR_DR(b) (b) +#define CIR_IER(b) (b + 1) +#define CIR_RCR(b) (b + 2) +#define CIR_TCR1(b) (b + 3) +#define CIR_TCR2(b) (b + 4) +#define CIR_TSR(b) (b + 5) +#define CIR_RSR(b) (b + 6) +#define CIR_BDLR(b) (b + 5) +#define CIR_BDHR(b) (b + 6) +#define CIR_IIR(b) (b + 7) + +/* Default Base address of Game port */ +#define GP_BASE_DEFAULT 0x0201 + +/* wdt_status */ +#define WDTS_TIMER_RUN 0 +#define WDTS_DEV_OPEN 1 +#define WDTS_KEEPALIVE 2 +#define WDTS_LOCKED 3 +#define WDTS_USE_GP 4 +#define WDTS_EXPECTED 5 + +static unsigned int base, gpact, ciract, max_units, chip_type; +static unsigned long wdt_status; + +static int nogameport = DEFAULT_NOGAMEPORT; +static int exclusive = DEFAULT_EXCLUSIVE; +static int timeout = DEFAULT_TIMEOUT; +static int testmode = DEFAULT_TESTMODE; +static bool nowayout = DEFAULT_NOWAYOUT; + +module_param(nogameport, int, 0); +MODULE_PARM_DESC(nogameport, "Forbid the activation of game port, default=" + __MODULE_STRING(DEFAULT_NOGAMEPORT)); +module_param(exclusive, int, 0); +MODULE_PARM_DESC(exclusive, "Watchdog exclusive device open, default=" + __MODULE_STRING(DEFAULT_EXCLUSIVE)); +module_param(timeout, int, 0); +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds, default=" + __MODULE_STRING(DEFAULT_TIMEOUT)); +module_param(testmode, int, 0); +MODULE_PARM_DESC(testmode, "Watchdog test mode (1 = no reboot), default=" + __MODULE_STRING(DEFAULT_TESTMODE)); +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started, default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT)); + +/* Superio Chip */ + +static inline int superio_enter(void) +{ + /* + * Try to reserve REG and REG + 1 for exclusive access. + */ + if (!request_muxed_region(REG, 2, WATCHDOG_NAME)) + return -EBUSY; + + outb(0x87, REG); + outb(0x01, REG); + outb(0x55, REG); + outb(0x55, REG); + return 0; +} + +static inline void superio_exit(void) +{ + outb(0x02, REG); + outb(0x02, VAL); + release_region(REG, 2); +} + +static inline void superio_select(int ldn) +{ + outb(LDNREG, REG); + outb(ldn, VAL); +} + +static inline int superio_inb(int reg) +{ + outb(reg, REG); + return inb(VAL); +} + +static inline void superio_outb(int val, int reg) +{ + outb(reg, REG); + outb(val, VAL); +} + +static inline int superio_inw(int reg) +{ + int val; + outb(reg++, REG); + val = inb(VAL) << 8; + outb(reg, REG); + val |= inb(VAL); + return val; +} + +static inline void superio_outw(int val, int reg) +{ + outb(reg++, REG); + outb(val >> 8, VAL); + outb(reg, REG); + outb(val, VAL); +} + +/* Internal function, should be called after superio_select(GPIO) */ +static void wdt_update_timeout(void) +{ + unsigned char cfg = WDT_KRST; + int tm = timeout; + + if (testmode) + cfg = 0; + + if (tm <= max_units) + cfg |= WDT_TOV1; + else + tm /= 60; + + if (chip_type != IT8721_ID) + cfg |= WDT_PWROK; + + superio_outb(cfg, WDTCFG); + superio_outb(tm, WDTVALLSB); + if (max_units > 255) + superio_outb(tm>>8, WDTVALMSB); +} + +static int wdt_round_time(int t) +{ + t += 59; + t -= t % 60; + return t; +} + +/* watchdog timer handling */ + +static void wdt_keepalive(void) +{ + if (test_bit(WDTS_USE_GP, &wdt_status)) + inb(base); + else + /* The timer reloads with around 5 msec delay */ + outb(0x55, CIR_DR(base)); + set_bit(WDTS_KEEPALIVE, &wdt_status); +} + +static int wdt_start(void) +{ + int ret = superio_enter(); + if (ret) + return ret; + + superio_select(GPIO); + if (test_bit(WDTS_USE_GP, &wdt_status)) + superio_outb(WDT_GAMEPORT, WDTCTRL); + else + superio_outb(WDT_CIRINT, WDTCTRL); + wdt_update_timeout(); + + superio_exit(); + + return 0; +} + +static int wdt_stop(void) +{ + int ret = superio_enter(); + if (ret) + return ret; + + superio_select(GPIO); + superio_outb(0x00, WDTCTRL); + superio_outb(WDT_TOV1, WDTCFG); + superio_outb(0x00, WDTVALLSB); + if (max_units > 255) + superio_outb(0x00, WDTVALMSB); + + superio_exit(); + return 0; +} + +/** + * wdt_set_timeout - set a new timeout value with watchdog ioctl + * @t: timeout value in seconds + * + * The hardware device has a 8 or 16 bit watchdog timer (depends on + * chip version) that can be configured to count seconds or minutes. + * + * Used within WDIOC_SETTIMEOUT watchdog device ioctl. + */ + +static int wdt_set_timeout(int t) +{ + if (t < 1 || t > max_units * 60) + return -EINVAL; + + if (t > max_units) + timeout = wdt_round_time(t); + else + timeout = t; + + if (test_bit(WDTS_TIMER_RUN, &wdt_status)) { + int ret = superio_enter(); + if (ret) + return ret; + + superio_select(GPIO); + wdt_update_timeout(); + superio_exit(); + } + return 0; +} + +/** + * wdt_get_status - determines the status supported by watchdog ioctl + * @status: status returned to user space + * + * The status bit of the device does not allow to distinguish + * between a regular system reset and a watchdog forced reset. + * But, in test mode it is useful, so it is supported through + * WDIOC_GETSTATUS watchdog ioctl. Additionally the driver + * reports the keepalive signal and the acception of the magic. + * + * Used within WDIOC_GETSTATUS watchdog device ioctl. + */ + +static int wdt_get_status(int *status) +{ + *status = 0; + if (testmode) { + int ret = superio_enter(); + if (ret) + return ret; + + superio_select(GPIO); + if (superio_inb(WDTCTRL) & WDT_ZERO) { + superio_outb(0x00, WDTCTRL); + clear_bit(WDTS_TIMER_RUN, &wdt_status); + *status |= WDIOF_CARDRESET; + } + + superio_exit(); + } + if (test_and_clear_bit(WDTS_KEEPALIVE, &wdt_status)) + *status |= WDIOF_KEEPALIVEPING; + if (test_bit(WDTS_EXPECTED, &wdt_status)) + *status |= WDIOF_MAGICCLOSE; + return 0; +} + +/* /dev/watchdog handling */ + +/** + * wdt_open - watchdog file_operations .open + * @inode: inode of the device + * @file: file handle to the device + * + * The watchdog timer starts by opening the device. + * + * Used within the file operation of the watchdog device. + */ + +static int wdt_open(struct inode *inode, struct file *file) +{ + if (exclusive && test_and_set_bit(WDTS_DEV_OPEN, &wdt_status)) + return -EBUSY; + if (!test_and_set_bit(WDTS_TIMER_RUN, &wdt_status)) { + int ret; + if (nowayout && !test_and_set_bit(WDTS_LOCKED, &wdt_status)) + __module_get(THIS_MODULE); + + ret = wdt_start(); + if (ret) { + clear_bit(WDTS_LOCKED, &wdt_status); + clear_bit(WDTS_TIMER_RUN, &wdt_status); + clear_bit(WDTS_DEV_OPEN, &wdt_status); + return ret; + } + } + return nonseekable_open(inode, file); +} + +/** + * wdt_release - watchdog file_operations .release + * @inode: inode of the device + * @file: file handle to the device + * + * Closing the watchdog device either stops the watchdog timer + * or in the case, that nowayout is set or the magic character + * wasn't written, a critical warning about an running watchdog + * timer is given. + * + * Used within the file operation of the watchdog device. + */ + +static int wdt_release(struct inode *inode, struct file *file) +{ + if (test_bit(WDTS_TIMER_RUN, &wdt_status)) { + if (test_and_clear_bit(WDTS_EXPECTED, &wdt_status)) { + int ret = wdt_stop(); + if (ret) { + /* + * Stop failed. Just keep the watchdog alive + * and hope nothing bad happens. + */ + set_bit(WDTS_EXPECTED, &wdt_status); + wdt_keepalive(); + return ret; + } + clear_bit(WDTS_TIMER_RUN, &wdt_status); + } else { + wdt_keepalive(); + pr_crit("unexpected close, not stopping watchdog!\n"); + } + } + clear_bit(WDTS_DEV_OPEN, &wdt_status); + return 0; +} + +/** + * wdt_write - watchdog file_operations .write + * @file: file handle to the watchdog + * @buf: buffer to write + * @count: count of bytes + * @ppos: pointer to the position to write. No seeks allowed + * + * A write to a watchdog device is defined as a keepalive signal. Any + * write of data will do, as we don't define content meaning. + * + * Used within the file operation of the watchdog device. + */ + +static ssize_t wdt_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + if (count) { + clear_bit(WDTS_EXPECTED, &wdt_status); + wdt_keepalive(); + } + if (!nowayout) { + size_t ofs; + + /* note: just in case someone wrote the magic character long ago */ + for (ofs = 0; ofs != count; ofs++) { + char c; + if (get_user(c, buf + ofs)) + return -EFAULT; + if (c == WD_MAGIC) + set_bit(WDTS_EXPECTED, &wdt_status); + } + } + return count; +} + +static const struct watchdog_info ident = { + .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, + .firmware_version = 1, + .identity = WATCHDOG_NAME, +}; + +/** + * wdt_ioctl - watchdog file_operations .unlocked_ioctl + * @file: file handle to the device + * @cmd: watchdog command + * @arg: argument pointer + * + * The watchdog API defines a common set of functions for all watchdogs + * according to their available features. + * + * Used within the file operation of the watchdog device. + */ + +static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + int rc = 0, status, new_options, new_timeout; + union { + struct watchdog_info __user *ident; + int __user *i; + } uarg; + + uarg.i = (int __user *)arg; + + switch (cmd) { + case WDIOC_GETSUPPORT: + return copy_to_user(uarg.ident, + &ident, sizeof(ident)) ? -EFAULT : 0; + + case WDIOC_GETSTATUS: + rc = wdt_get_status(&status); + if (rc) + return rc; + return put_user(status, uarg.i); + + case WDIOC_GETBOOTSTATUS: + return put_user(0, uarg.i); + + case WDIOC_KEEPALIVE: + wdt_keepalive(); + return 0; + + case WDIOC_SETOPTIONS: + if (get_user(new_options, uarg.i)) + return -EFAULT; + + switch (new_options) { + case WDIOS_DISABLECARD: + if (test_bit(WDTS_TIMER_RUN, &wdt_status)) { + rc = wdt_stop(); + if (rc) + return rc; + } + clear_bit(WDTS_TIMER_RUN, &wdt_status); + return 0; + + case WDIOS_ENABLECARD: + if (!test_and_set_bit(WDTS_TIMER_RUN, &wdt_status)) { + rc = wdt_start(); + if (rc) { + clear_bit(WDTS_TIMER_RUN, &wdt_status); + return rc; + } + } + return 0; + + default: + return -EFAULT; + } + + case WDIOC_SETTIMEOUT: + if (get_user(new_timeout, uarg.i)) + return -EFAULT; + rc = wdt_set_timeout(new_timeout); + case WDIOC_GETTIMEOUT: + if (put_user(timeout, uarg.i)) + return -EFAULT; + return rc; + + default: + return -ENOTTY; + } +} + +static int wdt_notify_sys(struct notifier_block *this, unsigned long code, + void *unused) +{ + if (code == SYS_DOWN || code == SYS_HALT) + wdt_stop(); + return NOTIFY_DONE; +} + +static const struct file_operations wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = wdt_write, + .unlocked_ioctl = wdt_ioctl, + .open = wdt_open, + .release = wdt_release, +}; + +static struct miscdevice wdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &wdt_fops, +}; + +static struct notifier_block wdt_notifier = { + .notifier_call = wdt_notify_sys, +}; + +static int __init it87_wdt_init(void) +{ + int rc = 0; + int try_gameport = !nogameport; + u8 chip_rev; + int gp_rreq_fail = 0; + + wdt_status = 0; + + rc = superio_enter(); + if (rc) + return rc; + + chip_type = superio_inw(CHIPID); + chip_rev = superio_inb(CHIPREV) & 0x0f; + superio_exit(); + + switch (chip_type) { + case IT8702_ID: + max_units = 255; + break; + case IT8712_ID: + max_units = (chip_rev < 8) ? 255 : 65535; + break; + case IT8716_ID: + case IT8726_ID: + max_units = 65535; + break; + case IT8718_ID: + case IT8720_ID: + case IT8721_ID: + max_units = 65535; + try_gameport = 0; + break; + case IT8705_ID: + pr_err("Unsupported Chip found, Chip %04x Revision %02x\n", + chip_type, chip_rev); + return -ENODEV; + case NO_DEV_ID: + pr_err("no device\n"); + return -ENODEV; + default: + pr_err("Unknown Chip found, Chip %04x Revision %04x\n", + chip_type, chip_rev); + return -ENODEV; + } + + rc = superio_enter(); + if (rc) + return rc; + + superio_select(GPIO); + superio_outb(WDT_TOV1, WDTCFG); + superio_outb(0x00, WDTCTRL); + + /* First try to get Gameport support */ + if (try_gameport) { + superio_select(GAMEPORT); + base = superio_inw(BASEREG); + if (!base) { + base = GP_BASE_DEFAULT; + superio_outw(base, BASEREG); + } + gpact = superio_inb(ACTREG); + superio_outb(0x01, ACTREG); + if (request_region(base, 1, WATCHDOG_NAME)) + set_bit(WDTS_USE_GP, &wdt_status); + else + gp_rreq_fail = 1; + } + + /* If we haven't Gameport support, try to get CIR support */ + if (!test_bit(WDTS_USE_GP, &wdt_status)) { + if (!request_region(CIR_BASE, 8, WATCHDOG_NAME)) { + if (gp_rreq_fail) + pr_err("I/O Address 0x%04x and 0x%04x already in use\n", + base, CIR_BASE); + else + pr_err("I/O Address 0x%04x already in use\n", + CIR_BASE); + rc = -EIO; + goto err_out; + } + base = CIR_BASE; + + superio_select(CIR); + superio_outw(base, BASEREG); + superio_outb(0x00, CIR_ILS); + ciract = superio_inb(ACTREG); + superio_outb(0x01, ACTREG); + if (gp_rreq_fail) { + superio_select(GAMEPORT); + superio_outb(gpact, ACTREG); + } + } + + if (timeout < 1 || timeout > max_units * 60) { + timeout = DEFAULT_TIMEOUT; + pr_warn("Timeout value out of range, use default %d sec\n", + DEFAULT_TIMEOUT); + } + + if (timeout > max_units) + timeout = wdt_round_time(timeout); + + rc = register_reboot_notifier(&wdt_notifier); + if (rc) { + pr_err("Cannot register reboot notifier (err=%d)\n", rc); + goto err_out_region; + } + + rc = misc_register(&wdt_miscdev); + if (rc) { + pr_err("Cannot register miscdev on minor=%d (err=%d)\n", + wdt_miscdev.minor, rc); + goto err_out_reboot; + } + + /* Initialize CIR to use it as keepalive source */ + if (!test_bit(WDTS_USE_GP, &wdt_status)) { + outb(0x00, CIR_RCR(base)); + outb(0xc0, CIR_TCR1(base)); + outb(0x5c, CIR_TCR2(base)); + outb(0x10, CIR_IER(base)); + outb(0x00, CIR_BDHR(base)); + outb(0x01, CIR_BDLR(base)); + outb(0x09, CIR_IER(base)); + } + + pr_info("Chip IT%04x revision %d initialized. timeout=%d sec (nowayout=%d testmode=%d exclusive=%d nogameport=%d)\n", + chip_type, chip_rev, timeout, + nowayout, testmode, exclusive, nogameport); + + superio_exit(); + return 0; + +err_out_reboot: + unregister_reboot_notifier(&wdt_notifier); +err_out_region: + release_region(base, test_bit(WDTS_USE_GP, &wdt_status) ? 1 : 8); + if (!test_bit(WDTS_USE_GP, &wdt_status)) { + superio_select(CIR); + superio_outb(ciract, ACTREG); + } +err_out: + if (try_gameport) { + superio_select(GAMEPORT); + superio_outb(gpact, ACTREG); + } + + superio_exit(); + return rc; +} + +static void __exit it87_wdt_exit(void) +{ + if (superio_enter() == 0) { + superio_select(GPIO); + superio_outb(0x00, WDTCTRL); + superio_outb(0x00, WDTCFG); + superio_outb(0x00, WDTVALLSB); + if (max_units > 255) + superio_outb(0x00, WDTVALMSB); + if (test_bit(WDTS_USE_GP, &wdt_status)) { + superio_select(GAMEPORT); + superio_outb(gpact, ACTREG); + } else { + superio_select(CIR); + superio_outb(ciract, ACTREG); + } + superio_exit(); + } + + misc_deregister(&wdt_miscdev); + unregister_reboot_notifier(&wdt_notifier); + release_region(base, test_bit(WDTS_USE_GP, &wdt_status) ? 1 : 8); +} + +module_init(it87_wdt_init); +module_exit(it87_wdt_exit); + +MODULE_AUTHOR("Oliver Schuster"); +MODULE_DESCRIPTION("Hardware Watchdog Device Driver for IT87xx EC-LPC I/O"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |